| 1. |
- Tunik, S P, et al.
(författare)
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Reactions of [H2OS3(CO)(10)] with conjugated diynes (RC2C2R ') containing nucleophilic oxygen in beta position of a substituent (R = Ph, R ' = CH2OH, C(O)Ph; R = R ' = CMe2(OH))
- 2003
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Ingår i: Organometallics. - : American Chemical Society (ACS). - 1520-6041 .- 0276-7333. ; 22:17, s. 3455-3465
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Tidskriftsartikel (refereegranskat)abstract
- Reactions of [H2Os3(CO)10] with a series of diynes, RC2C2R' (1: R = Ph, R' = CH2OH; 2: R = Ph, R' = C(O)Ph; 3: R = R' = C(OH)Me2), have been studied. It was found that upon coordination to the triosmium cluster, the nucleophilic oxygens of the R' substituents of 1 and 2 take part in intramolecular cyclization reactions to give [HOs3(CO)10{-1:2-PhCH2(C=CH-C=CH-O)}] (5) and [HOs3(CO)10{-1:1-Ph(C=CH-C=C-O)CPh}] (6), respectively, both of which contain furan rings coordinated to the cluster core. On heating of the latter compound, the furan moiety remains intact, but a carbonyl group dissociates from the cluster, leading to the formation of [HOs3(CO)9(3-1:3:1-Ph(C=CH-C=C-O)CPh)] (7) with a closed "C3Os3" pentagonal pyramidal structure. Reaction of [H2Os3(CO)10] with 3 does not lead to cyclization of the diyne; instead, the clusters [Os3(CO)10{3-2-(RCH=CH-C2R)}] (8) and [Os3(CO)10{3-2-(RC2C2R)}] (9) are formed. Deuterium labeling of the starting compounds has been used in the reaction of [H2Os3(CO)10] with HOCH2C2C2CH2OH in order to investigate possible mechanisms of the cyclization reaction. The crystal and molecular structures of clusters 5, 7, and 9 are presented.
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| 2. |
- Tunik, S P, et al.
(författare)
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Chiral hexarhodium clusters containing heterobidentate phosphine ligands, a structural and reactivity study
- 2003
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Ingår i: Dalton Transactions. - : Royal Society of Chemistry (RSC). - 1477-9234. ; :12, s. 2457-2467
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Tidskriftsartikel (refereegranskat)abstract
- Some intrinsically chiral [Rh6(CO)14(µ,2-PX)] clusters have been synthesized, beginning with reactions of [Rh6(CO)16–x(NCMe)x](x= 1, 2) with PX, where PX represents the bidentate bridging ligands diphenyl(benzothienyl)phosphine (1), diphenyl(2-thienyl)phosphine (2), di(2-thienyl)phenylphosphine (3), tris(2-thienyl)phosphine (4), diphenyl(2-pyridyl)phosphine (5) and diphenylvinylphosphine (6). The ligand tris(2-furyl)phosphine (7) shows no bridging capability. When x= 1 the initial products are the clusters [Rh6(CO)15(1-PX)] which undergo spontaneous CO loss to form [Rh6(CO)14(µ,2-PX)]. The structures of the [Rh6(CO)15(1-PX)] clusters have been elucidated by IR, NMR spectroscopy and FAB-MS spectrometry, and have been found to involve phosphorus atom coordination to a rhodium atom. In addition, the solid state structures of the [Rh6(CO)14(µ,2-Ph2P(2-benzothienyl))](8), [Rh6(CO)14(µ,2-Ph2P(2-thienyl))](9), [Rh6(CO)14(µ,2-PhP(2-thienyl)2)](10) and [Rh6(CO)14(µ,2-Ph2P(pyridyl))](12) clusters have been determined by X-ray crystallography. The various types of chirality exhibited by these clusters are discussed. A simple model is proposed to account for the ratios of stereochemical isomers found in the Rh6(CO)14(µ,2-PhP(2-thienyl)2 cluster. The kinetics of formation of the bridged clusters from the monosubstituted [Rh6(CO)15(1-PX)] clusters have been studied.
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